Paint



Patented May 11, 1926.

[UNITED STATES PATENT OFFICE.

PAINT.

Nb Drawing.

This case is a continuation in part of application Number 532,725, filed J anuary 30, 1922, and a continuation in part of application Number 431,473, filed December 17, 1920.

This invention relates to a paint, consisting of lead suboxide powder intermingled with powder of metallic lead of a very small apparent specific gravity combined with boiled oil, or a mixture of boiled oil and resin, or any other vehicle generally used in paints, and the object thereofisto obtain a paint having a great cover ng capacity and extensibility, at the same time acting as an anti-corrosive as well as antifouling paint, the chemically reactlveforce of lead suboxide powder being utilized for the latter purposes.

The lead suboxide powder used in this invention is obtained in dried condition by, abrading mechanically successive films formed on lead pieces exposed to the 'air and kept at a temperature not lessthan 60 C. The lead suboxide powder intermingled with metallic lead powder thus obtained has special properties different from those of lead suboxide hitherto known, and is spongy and porous,'having an apparent specific gravity 'of 13. Exposed-to water or moisture, it is instantly converted into lead monoxide, lead hydroxide or basic lead hydroxide. It is so chemically reactive that if'a few drops of water be dropped on a pile of it, or a lightedm'atch be applied thereto, it ignites as if it were sulphur or such easily inflammable substance, until the whole of the pile is converted into litharge. The lead, suboxide powder intermingled with metallic powder used in this invention is thus chemically very active but is not unstable as such powder manufactured chemically by reducing'lead oxalate, and is very convenient to handle and preserve for industrial purposes. It is of such special'qualities, and used in the place of red lead, it

proves not only to be a veryeflicient p-igment, but is also anti-corrosive and antifouling on account of its reducible and poisoning properties. 3

To show an example of carrying my invention into practice, round pieces of lead are put in a revolvable drum together with steel balls, and the drum is slowly revolved, introducing thereinto air or any other oxidizinggas. Then the heat generated by friction and, oxidation of the lead pieces will Application filed April 18, 1924. Serial No. 707,510.

keep the interior of the drum at a temperature not less than 60 C., and films of lead suboxide will beforme'd on the face of the lead pieces. The films of lead suboxide sues cessively formed on the lead pieces are successively abraded ofl', and a very fine andv chemically reactive lead 'suboxide-powder intermingled with a small proportion of powder of metallic lead is produced. Such powder is then mixed with boiled oil, varnish vehicle, solution of casein, cellulose esters, lacquers, .or any other vehicle of paints, and is kneaded; and a paint of a suitable consistency'will be obtained. When the paint of my invention is spread over the surface of iron or any other metal, or wood,

and exposed to the air, it gets gradually,

oxidized in a natural way as the vehicles dries, forming finally a' compact. layer of oxide just like one formed spontaneously on the polished surface of a metal, and serves as a very efi'icient protective film. The surplus lead suboxide and metallic lead act as a strong poison against living organisms, such as shell fish, worms, insects, sea-weeds, and bacteria, and serves to prevent their attachmcnt. j

The paint of my invention possesses, moreover, a. covering capacity and an extensibility several times greater than ordi nary red lead paint. It makes, therefore, a very efiicient and convenient anti-corrosive and anti-septic paint, it being especially efiicientand economical for painting the ships A bottom, because with'my' paint one need not go through the trouble of giving to the ship first an anti-corrosive coating, and then when it has dried, a second coating of antifouling paint, but only one coating efficiently attains the two objects.

The inventor is aware that powder of lead suboxide, or metallic lead,'is used as a material of paints, but the lead suboxide powder intermingled with metallic lead, used in this invention has characteristics quite different from those of hitherto known lead suboxide,

or metallic lead, powder, and by using the powder having such special characteristics, the inventor has been. enabled to secure special efiiciency. It is firmly believed that T this application therefore constitutes a new invention.

Claims.

1. A paint comprising a vehicle and a finely divided chemically reactive powder fc ntd fiiiga major proportion of lead suboxide and a minor proportion of metallic lead, said powder resulting from the impingement of a current of air on relatively large masses of lead in a dry state, subjecting the lead to surface attrition, controlling the temperatureto cause the formation of lead suboxide in the said proportions, and carrying of the powder resulting from the above by the said current of air.

2. A paint comprising a vehicle and a finely divided chemically reactive powder containing a major proportion of lead suboxide and a minor proportion of metallic lead, said powder resulting from the impinge'ment of a current of air on relatively large masses of lead in a dry state, subjecting the lead to surface attrition, controlling the temperature to be not less than sixty degrees centigrade, so as to form powder containing lead suboxide in the above'proportions and carrying of the powder so formed by the above mentioned current of air.

' In testimony whereof I have afiixed my signature.

GENZO SHIMADZU. 

